Method and assembly used for vector transfer

ABSTRACT

A method for transmitting a vector having at least two vector components, each of the vector components described in a frequency. Each vector is represented as a bit number with a predetermined number of bit levels. The bit numbers are encoded according to a priority of the bit levels and the encoded bit numbers are transmitted.

[0001] The invention relates to a method and arrangement for vectortransmission.

[0002] A method of this kind is known from [1] or [2] and there it isused for the processing of multimedia information.

[0003] In previous years, various standards were specified for theencoding of multimedia information, e.g. video information or audioinformation.

[0004] An example of such a standard is the image coding standard MPEG4[3].

[0005] These common standards have meant that evermore multimediainformation is available. To be able to make this information availableto users, it is necessary to index this multimedia information.

[0006] Such indexing is normally carried out by descriptors, as they arecalled, that describe features of multimedia information. Examples ofsuch features are the color distribution or brightness distribution of adigitized image.

[0007] These descriptors are frequently histogram based, i.e. afrequency of a value of a feature to be described is determined.

[0008] Such a histogram in the context of a description of a colordistribution of a digitized image is known from [1] or [2]. With thishistogram, a color histogram, a frequency is described, with which aspecific color value or color range occurs as an image element in animage.

[0009] Because such a histogram normally has very many entries, acomparison of such histograms is expensive. Furthermore, adjacententries frequently have similar values.

[0010] The transformation of a histogram, in this case using a Haarwavelet transformation, is known from [1] or [2].

[0011]FIG. 2 shows a schematic of the use of a Haar wavelettransformation (200), as is known from [1] or [2], on a one-dimensional4-bin histogram, i.e. a histogram with four frequency entries.

[0012] By means of this transformation (200), that is a combination ofspecified arithmetic operations, i.e. an addition (201) and asubtraction (202), four entries of the 4-bin histogram, a Value Bin 0(210), a Value Bin 1 (220), a Value Bin 2 (230) and a Value Bin 3 (240)are depicted, in accordance with FIG. 2, on four Haar waveletcoefficients, a Haar Coeff Index 0 (250), a Haar Coeff Index 1 (260), aHaar Coeff Index 2 (270) and a Haar Coeff Index 3 (280).

[0013] These Haar wavelet coefficients, as already known from [1] or[2], are then quantized, binarized, i.e. each quantized Haar waveletcoefficient is converted to a corresponding binary number or digitstring of binary digits 0 and 1 each with a fixed bit length that can bespecified and then encoded to form a bit data stream. There, this bitdata stream is compared with a comparison bit data stream that wasencoded in a corresponding manner and also describes a histogram.

[0014] By means of this procedure, it is possible to compare twohistograms by using their associated bit data streams, without inversetransformation of the bit data streams back to the associated histogramsbeing necessary.

[0015]FIG. 3 is a schematic showing the procedure for this encoding inaccordance with [1] or [2].

[0016]FIG. 3 shows a bit level representation (300) of four binarized,quantized Haar wavelet coefficients (301 to 304), that have seven bitlevels (301 to 316) in accordance with FIG. 3.

[0017] With this encoding (320), known from [4], the four Haar waveletcoefficients (301 to 304) are entered in succession, each correspondingto a reducing bit priority of the associated binary digits in the bitdata stream (350).

[0018] This is achieved in that with the encoding (320) of the Haarwavelet coefficients (301 to 304), the binary digit of the associatedmost significant bit level, called a most significant bit (MSB) (331) isfirst entered in the bit data stream (350). As the last bit to beencoded of the particular Haar wavelet coefficients (301 to 304), thebinary digit of the lowest order bit level (0 bit level (301)), called aleast significant bit (LSB) 332, is entered in the bit data stream(350).

[0019] The result of this is that the binary digits of coded Haarwavelet coefficient (361 to 367) are entered in the bit data stream(350) separately from those of the succeeding encoded Haar waveletcoefficients (371 to 374).

[0020] The transmission of such a bit data stream to a receiver and itscomparison there with a further bit data stream encoded in the same way,that represents a histogram to be compared, is also known from [1] or[2].

[0021] However, this known procedure has the disadvantage thatinformation encoded in the bit data stream is transmitted in such a waythat unnecessary information also has to be transmitted in the bit datastream for a rough comparison of the two histograms. The result of thisis that the transmission bandwidth used for such a comparison cannot bereduced.

[0022] The object of the invention is therefore to provide a method, andalso an arrangement, by means of which method and arrangement atransmission of encoded information that describes a frequency ispossible, that is better and more efficient than the known method.

[0023] The object is achieved by the method and arrangement with thefeatures in accordance with the relevant independent patent claim.

[0024] With the method for transmitting a vector with at least twovector components each of which describes a frequency, each vectorcomponent is shown as a bit number with a predetermined number of bitlevels. The bit numbers are then encoded and transmitted according to apriority of the bit levels.

[0025] A processor, that is set up so that the following steps can beperformed, has an arrangement for transmitting a vector with at leasttwo vector components, each of which describes a frequency.

[0026] Each component is shown as a bit number with a predeterminednumber of bit levels and

[0027] The bit numbers are encoded and transmitted according to apriority of the bit levels.

[0028] A particular advantage of the invention is the memory structureof the binary digits in the bit data stream. The binary digits areentered in the bit data stream in such a way that the first binarydigits in the bit data stream are used for a rough comparison of twohistograms. In this way, a comparison of this kind can be performedfaster and more effectively. The bandwidth used to transmit the bit datastream can also be reduced.

[0029] The invention also enables a fast scaling of a vectorrepresentation. From a precise vector representation by elimination ofthe last binary digits, i.e. of binary digits of least significant bitlevels, the memory structure of the binary digits enables a rough vectorrepresentation to be created without re-sorting binary digits. Becausethis is a frequent operation in the transmission and comparison ofhistograms, this advantage is of great significance.

[0030] Furthermore, the invention enables a fast comparison of vectors.The binary digits of important components of a vector are encoded at thestart of each bit level and can be directly read.

[0031] The arrangement is particularly suitable for performing themethod in accordance with the invention or one of its developmentsexplained in the following.

[0032] Preferred developments of the invention result from thesubclaims.

[0033] The further described developments refer both to the method andthe arrangement.

[0034] The invention and the further described developments can berealized in the software, and also in the hardware, for example by usinga special electrical circuit.

[0035] Furthermore, a realization of the invention or a furtherdescribed development is possible by a computer-readable memory mediumon which a program that performs the invention or development is stored.

[0036] The invention, or any development further described, can also berealized by a computer program product that has a memory medium on whicha computer program is stored that performs the invention or development.

[0037] In one embodiment, the vector is a coefficient vector withcoefficients that were determined using a transformation, for example aHaar wavelet transformation.

[0038] The vector can also be quantized before the binarization of thevector components.

[0039] In one development, the vector represents a histogram. Ahistogram of this kind generally contains histogram entries, each ofwhich describes a frequency.

[0040] The histogram is preferably subjected to a Haar transformation sothat data can thus be reduced without loss of information. A furtherreduction of data is obtained if the transformed histogram is quantized.

[0041] With a development of the invention that uses a digitized imageduring encoding, the histogram describes a frequency distribution, forexample a color or brightness distribution, based on the digitizedimage.

[0042] The vector components are preferably sorted corresponding to apredetermined sequence. In this way, a selection of data to be encodedor transmitted can be made and the efficiency of the encoding ortransmission thus increased.

[0043] A further improvement in the encoding efficiency is achieved inthat only a predetermined number of bit levels are encoded. In this caseit is advantageous to encode high-order bit levels. The encodedinformation stored in such bit levels is more important than that inlow-order bit levels.

[0044] A further improvement of the encoding efficiency is obtained ifthe bit numbers are encoded according to a reducing priority of the bitlevels.

[0045] The illustrations show an example of an embodiment of theinvention that is further explained in the following.

[0046] The illustrations are as follows.

[0047]FIG. 1 A sketch describing the steps of a method for encoding andtransmitting information in accordance with an example of an embodiment.

[0048]FIG. 2 A sketch that schematically describes a Haar wavelettransformation.

[0049]FIG. 3 A sketch that describes the encoding of a Haar waveletcoefficient in accordance with prior art.

[0050]FIG. 4 A sketch that schematically describes a Haar wavelettransformation in accordance with an example of an embodiment.

[0051]FIG. 5 A sketch that describes the encoding of a Haar waveletcoefficient in accordance with an example of an embodiment.

[0052]FIG. 6 A sketch that describes an encoding in accordance with afirst alternative to an example of the embodiment, whereby a sequence ofthe binary numbers is changed.

[0053]FIG. 7 A sketch that describes an encoding in accordance with asecond alternative to an example of the embodiment, with only selectedbit levels being encoded.

EXAMPLE OF AN EMBODIMENT

[0054] Encoding and Transmission of a Color Histogram

[0055] The example of an embodiment described in the following refers tothe encoding and transmission of a color histogram.

[0056]FIG. 1 is a schematic illustration of the method steps in whichthe coding and transmission of the color histogram is performed.

[0057] The following is a summary giving details of the proceduralsteps.

[0058] The color histogram is determined in a first procedural step 101.A Haar wavelet transformation is applied to the color histogram in asecond procedural step 102. The Haar transformed histogram is quantizedin a third procedure step 103. In a fourth procedural step 104, valuesof the Haar-transformed and quantized histogram are binarized in such away that each binary value has a predetermined number of bit levels. Thebinary values are then encoded in a bit data stream according to apriority of the bit levels, in a fifth procedural step 105. The bit datastream is transmitted in a sixth procedural step 106.

[0059]FIG. 4 shows the color histogram, a one-dimensional 4-binhistogram 401 with four histogram entries 401 to 404, that describes acolor distribution of a digitized color image.

[0060] This color histogram 400 describes a frequency at which a certaincolor range occurs as an image element in the digitized color image.

[0061] In this case, the frequency of a specific color range correspondsto the associated entry 471, 472, 473 or 474 in the color histogram 400.

[0062]FIG. 4 also schematically illustrates an application of a Haarwavelet transformation 410, as described in [1] or [2], to the colorhistogram 400.

[0063] By means of this Haar wavelet transformation 410, that is acombination of predetermined arithmetic operations, i.e. an addition 411and a subtraction 412, the four entries of the color histogram, a ValueBin 0 401, a Value Bin 1 402, a Value Bin 2 403, a Value Bin 3 404 aredepicted on four Haar wavelet coefficients, a Haar Coeff Index 0 420, aHaar Coeff Index 1 421, a Haar Coeff Index 2 422 and a Haar Coeff Index3 423.

[0064] These Haar wavelet coefficients 420 to 423 are, as also describedin [1] or [2], quantized and then binarized, i.e. each quantized Haarwavelet coefficient is converted to a corresponding binary number ordigit string of binary digits 0 and 1, each with a fixed, presettablebit length.

[0065]FIG. 5 is a schematic representation of the binary digit strings501 to 504 in a bit level representation.

[0066] A first digit string 501 has a bit length with 7 bits. A seconddigit string 502 has a bit length with 4 bits. A third digit string 503has a bit length with 6 bits and a fourth digit string has a bit lengthwith 3 bits.

[0067] The number of bit levels used in the illustration depends on themaximum bit length of all digit strings. Thus, seven bit levels 510 to516 corresponding to the bit length of first digit string 501 are shownin FIG. 5. Bit levels 510 to 516 are arranged relative to each othercorresponding to their priority, i.e. bit level 511 is on bit level 510,bit level 512 is on bit level 511 etc.

[0068] Corresponding to the particular bit length, all seven bit levels510 to 516 of the first digit string 501, the four bit levels 510 to 513of the second digit string 502, the six bit levels 510 to 515 of thethird digit string and bit levels 510 to 512 of the fourth digit string504 are occupied, according to the bit length in each case.

[0069] During the encoding 530 of the binary digit strings 501 to 504 inthe bit data stream 540, the digits of the highest bit level, in thiscase the seventh bit level 516, are first entered in the bit data stream540.

[0070] Because in this case only the first digit string 501 has a digit550, that belongs to the seventh bit level 516, only this digit 550 isentered in the bit data stream 540.

[0071] Digits 551 and 552, that belong to the next-lower bit level, bitlevel 515, are then entered in the bit stream 540.

[0072] In this way, the remaining bit levels 514, 513, 512, 511 and 510are each processed according to reducing priority. Bit level 510 isprocessed as the last bit level.

[0073] Digits that belong to the same bit level are entered in thesequence of the associated binary numbers, in this case in the sequence501, 502, 503 and 504, in the bit data stream 540.

[0074] Thus the encoding 530 of the digit strings 501 to 504 in the bitdata stream takes place according to the priority of the bit level towhich the digit to be encoded belongs. The only prioritizing feature inthis case is the sequence of the binary numbers.

[0075] The bit data stream 540 is then transmitted to a receiver.

[0076] Alternatives to the first example of an embodiment are describedin the following.

[0077] First alternative: Re-sorting the binary numbers or digit stringsbefore encoding.

[0078]FIG. 6 shows a first alternative to the first example of anembodiment.

[0079] In this first alternative, the sequence of the binary numbers ordigit strings 601 to 604 are changed by re-sorting before the encoding630 in the bit data stream 640.

[0080] The new sequence of binary numbers or digit strings is then: 601before 603 before 602 before 604.

[0081] The new re-sorted sequence of binary numbers or digit strings 601to 604 takes account of frequencies of the frequency changes,represented by the binary numbers or digit strings 601 to 604, in ahistogram with regard to color ranges of the digitized color image.

[0082] The new first digit string 601 represents the frequency range ofthe smallest frequencies. The next-higher frequency range is representedby the new second digit string 603. The new third digit string 602 andthe new fourth digit string 604 represent the frequency ranges with thegreatest frequencies.

[0083] It is to be noted that the new sequence does not represent anylimitation of the re-sorting. Any sequence of digit strings can berealized.

[0084] The encoding 630 of the new sorted digit strings 601 to 604 inthe bit data stream 640 takes place according to the first example of anembodiment.

[0085] In this case also, the encoding 630 of the digit strings 601 to604 in the bit data stream takes place according to the priority of thebit level to which the digit to be encoded belongs. The onlyprioritizing feature in this case is also the new re-sorted sequence ofthe binary numbers or digit strings 601 to 604.

[0086] Second alternative: Encoding of selected bit levels only

[0087]FIG. 7 shows a second alternative to the first example of anembodiment.

[0088] In this second alternative, the bit levels to be encoded areselected. In this second alternative only the digits of the upper fourbit levels 716, 715, 714 and 713 are coded in the bit data stream 740.

[0089] This selection is not to be regarded as a limitation of theselection of bit levels to be encoded. It should be noted that any ofthe bit levels to be encoded can be selected.

[0090] The digits of the selected bit levels 716, 715, 714 and 713 areencoded 730 according to the first example of an embodiment.

[0091] In this case also, the encoding 730 of the digit strings 701 to704 in the bit data stream takes place according to the priority of thebit level to which a digit to be encoded belongs. The only prioritizingfeature in this case is also the sequence of the binary numbers or digitstrings 701 to 704.

[0092] It should be noted that in addition to selecting the bit levelsto be encoded, it is also possible to re-sort the binary numbers inaccordance with the first alternative (combination of first and secondalternatives).

[0093] The following publications are cited in this document.

[0094] [1] Jens-Rainer Ohm, Bela Makai, Results of CE CT5 on scalablerepresentation of color histograms, ISO/IEC JTC1/SC29/WG11 M6031, May2000, Geneva.

[0095] [2] Jens-Rainer Ohm, Bela Makai, Aljoscha Smolic, Results of CECT5 on scalable representation of color histograms, ISO/IECJTC1/SC29/WG11 M6285, July 2000, Beijing.

[0096] [3] MPEG-4 applications, obtainable on 04.10.2000 underhttp://www.cselt.it/mpeg/public/mpeg-4 applicatons.zip

[0097] [4] Jens-Rainer Ohm, Digitale Bildcodierung [Digital imagecoding] pages 284-285, Springer Verlag, 1995, Berlin.

1. Method of transmitting a vector with at least two vector components,each of which describes a frequency, with each vector component beingrepresented as a bit number with a predetermined number of bit levelsand with the bit numbers being encoded according to a priority of thebit levels and transmitted.
 2. Method in accordance with claim 1, withthe vector being a coefficient vector with coefficients that weredetermined by using a transformation.
 3. Method in accordance with claim2, with the coefficient vector being quantized.
 4. Method in accordancewith one of claims 1 to 3, with the vector representing a histogram. 5.Method in accordance with claim 4, with the histogram describing afrequency distribution or color or brightness distribution based on adigitized image.
 6. Method in accordance with one of claims 1 to 5, withthe vector components being sorted according to a predeterminedsequence.
 7. Method in accordance with one of the claims 1 to 6, withonly a predetermined number of bit levels being coded.
 8. Method inaccordance with one of claims 1 to 7, with the bit numbers being codedaccording to a reducing priority of bit levels.
 9. Arrangement fortransmitting a vector with at least two vector components, each of whichdescribes a frequency, with a processor set up in such a way that thefollowing steps can be executed. Each vector component is represented asa bit number with a predetermined number of bit levels and The bitnumbers are encoded according to a priority of the bit levels andtransmitted.